This invention relates to tools for holding a workpiece, and more particularly, to a tool for holding a video tape cassette to facilitate inspection, repair and adjustment of the cassette.
A conventional video tape cassette comprises a polyethylene-base magnetic tape wound on a pair of reels inside a housing, and includes a closure or tape shield attached by hinges and under spring tension to the body of the cassette. The shield, normally locked into a position along one edge of the cassette housing for covering and protecting the video tape, can be manually unlocked and opened to expose the tape.
When the cassette is inserted into a video playback or recording machine, a mechanism in the machine releases the shield lock, swings the shield open and away from the video tape, and positions the cassette so that the tape, now exposed along one edge of the cassette, can be threaded into the machine and held against the video drum and audio heads. When the cassette is removed from the video machine, the shield, under spring tension, automatically closes and locks into place, covering and protecting the video tape from damage.
Conventional video-tape cassettes often include an internal mechanism for locking the tape reels when the cassette is removed from the video machine, thereby preventing the tape from becoming loose on the reels. When a cassette having reel locks is inserted into a video machine and positioned on the reel hubs for operation, a pin protruding from the machine is received into an aperture in the housing of the cassette, where the pin engages an unlocking mechanism inside the cassette, releasing the tape reels for movement by the machine.
After a period of use, the tape may become improperly tensioned, which can cause tape damage or breakage. Therefore it is beneficial to periodically release the tape reel locks and manually adjust tape tension. Video tape cassettes are also inspected periodically with use, and repaired or adjusted if required. To inspect, repair or retension a video tape cassette, it was heretofore necessary either to disassemble the cassette, or to release the shield-locking mechanism by hand, manually open and hold the shield to gain access to the video tape or the internal mechanisms of the cassette, and effect inspection, repair or adjustment while holding the shield open against spring tension. Furthermore, if the cassette included a reel locking device, it was necessary to release the reel locks manually by inserting a suitable rod or pin into the reel-lock aperture, while simultaneously holding the spring-loaded tape shield open, thus making inspection, repair or retensioning of the cassette cumbersome, time consuming and difficult.
Accordingly, it is an object of my invention to provide an improved tool for holding a workpiece.
It is another object of my invention to provide an improved tool for holding a video tape cassette while effecting inspection, repair and adjustment thereof.
Still another object of the invention is to provide an improved hand tool for holding open the tape shield of a video tape cassette while effecting inspection, repair or adjustment of the cassette.
It is another object of the invention to provide an improved tool for releasing the reel locks of a video tape cassette.